Hi everyone, on 3-OCT-05 while an annular eclipse of the Sun is visible in Europe and Africa observers on the opposite side of the globe can see this eclipse in an indirect way by looking at some geostationary satellites. GEOs close to 140.9 deg East will experience an annular eclipse at around 13:30 UTC. These satellites can be observed under dark skies from Australia, New Zealand, East Asia and Hawaii. The expected drop in brightness of the GEOs due to the eclipse should be about mag 1.5 of which 1 mag happens during the final 8 minutes before annularity. (At the position of the GEOs in question the Moon is further away and covers a smaller fraction of the Sun that it does for observers on the other side of the globe - that's why the drop in magnitude is not bigger.) Here are six GEOs which will experience an annular eclipse (all times are UTC): MBSAT 28184 144.1E 13:06 - 13:39 (annular from 13:21:24 - 13:22:31) SUPERB.C 24880 144.0E 13:06 - 13:39 (annular from 13:21:37 - 13:22:43) HIMARARI6 28622 140.4E 13:17 - 13:51 (annular from 13:32:21 - 13:34:52) BEIDOU1 26599 140.1E 13:18 - 13:51 (annular from 13:33:05 - 13:35:28) EXPR.AM3 28707 140.1E 13:18 - 13:51 (annular from 13:33:16 - 13:35:46) APSTAR5 28364 138.0E 13:25 - 13:58 (annular from 13:40:27 - 13:41:27) Note that the shadow moves from East to West in this case contrary to how it moves on the ground. Between 2 and 5 minutes after the end of the (partial phase of) the eclipse (depending on the position) the satellites will enter Earth shadow for one hour. This means that satellite operators will have to rely on battery power for a longer than usual time. I'd appreciate any reports about this event, particularly the actually observed drop in magnitude of the GEOs. Gerhard HOLTKAMP Darmstadt, Germany ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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